Arrange the vehicles in descending order according to the altitudes at which they operate.

\begin{tabular}{|c|c|}
\hline
Vehicle & Altitude (feet) \\
\hline
sailboat & 0 \\
\hline
submarine & [tex]$-1,500$[/tex] \\
\hline
glider & 5,000 \\
\hline
airship & 3,000 \\
\hline
\end{tabular}

A. sailboat, submarine, glider, airship

B. submarine, sailboat, airship, glider

C. airship, glider, submarine, sailboat

D. glider, airship, sailboat, submarine



Answer :

To solve the problem of arranging the vehicles by their altitudes in descending order, we need to compare the altitudes listed for each vehicle:

- Sailboat: 0 feet
- Submarine: -1500 feet (since it's below sea level)
- Glider: 5000 feet
- Airship: 3000 feet

Let's place these altitudes in descending order, starting from the highest altitude:

1. Glider: 5000 feet
2. Airship: 3000 feet
3. Sailboat: 0 feet
4. Submarine: -1500 feet

This order places the vehicle with the highest altitude first and continues in decreasing order of altitude.

Accordingly, the correct sequence of vehicles in descending order of altitude is:

- Glider (5000 feet)
- Airship (3000 feet)
- Sailboat (0 feet)
- Submarine (-1500 feet)

This corresponds to option D: glider, airship, sailboat, submarine.

Thus, the correct answer is:
[tex]\[ \boxed{D} \][/tex]